package ctn.web.home.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.SocketException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.net.SocketException;

import org.apache.commons.lang.RandomStringUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class VCodeProvider extends HttpServlet{
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	/*@RequestMapping(value="/GetSecCode")
	public void index(HttpServletRequest request,
			HttpServletResponse response){
		genValidateCode(request, response);
	}*/
	
	@Override
	@RequestMapping(value="/GetSecCode")
	public void service(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		genValidateCode(request, response);
	}

	private void genValidateCode(HttpServletRequest request,HttpServletResponse response){
		int width = 50;
		int height = 20;
		// 取得一个4位随机字母数字字符串
		String s = RandomStringUtils.random(4, true, true);
		// 保存入session,用于与用户的输入进行比较.
		// 注意比较完之后清除session.
		HttpSession session = request.getSession(true);
		session.removeAttribute("validateCode");
		session.setAttribute("validateCode", s);

		response.setContentType("images/jpeg");
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);

		ServletOutputStream out = null;
		try {
			out = response.getOutputStream();
			BufferedImage image = new BufferedImage(width, height,
					BufferedImage.TYPE_INT_RGB);
			Graphics g = image.getGraphics();
			// 设定背景色
			g.setColor(getRandColor(200, 250));
			g.fillRect(0, 0, width, height);

			// 设定字体
			Font mFont = new Font("Times New Roman", Font.BOLD, 18);// 设置字体
			g.setFont(mFont);

			// 画边框
			// g.setColor(Color.BLACK);
			// g.drawRect(0, 0, width - 1, height - 1);

			// 随机产生干扰线，使图象中的认证码不易被其它程序探测到
			g.setColor(getRandColor(160, 200));
			// 生成随机类
			Random random = new Random();
			for (int i = 0; i < 155; i++) {
				int x2 = random.nextInt(width);
				int y2 = random.nextInt(height);
				int x3 = random.nextInt(12);
				int y3 = random.nextInt(12);
				g.drawLine(x2, y2, x2 + x3, y2 + y3);
			}

			// 将认证码显示到图象中
			g.setColor(new Color(20 + random.nextInt(110),
					20 + random.nextInt(110), 20 + random.nextInt(110)));

			g.drawString(s, 2, 16);
			
			// 图象生效
			g.dispose();
			
			// 输出图象到页面
			ImageIO.write((BufferedImage) image, "JPEG", out);
			out.close();
		}catch (Exception e) {
			//System.out.println(e.getClass());
			//e.printStackTrace();
		}
	}
	
	// 产生随机的背景颜色
	private Color getRandColor(int fc, int bc) {
		Random r = new Random();
		if (fc > 255)
			fc = 255;
		if (bc > 255)
			bc = 255;
		int red = fc + r.nextInt(bc - fc);// 红
		int green = fc + r.nextInt(bc - fc);// 绿
		int blue = fc + r.nextInt(bc - fc);// 蓝
		return new Color(red, green, blue);
	}

}
